convert vob to imovie

I have been using DVD backup to copy dvd’s to my hard drive, does anyone know how to extract short clips from the vob.
Perhaps convert the files to imovie.
JS

I have had the best luck with Handbrake. You can use the DVD as input. Select the chapters you want and it will create an mp4 file (sound and video). This can be played with Quicktime or you can drag it right into iMovie HD.